Method of driving piles



Sept. 26, 1961 K. HAAGE METHOD OF DRIVING PILES 2 Sheets-Sheet 1 FiledApril 20. 1959 AVVE/l/TOP z r aa/ flee we Sept. 26, 1961 K. HAAGE3,001,515

METHOD OF DRIVING FILES Filed April 20. 1959 2 Sheets-Sheet 2 3,001,515METHOD OF DRIVING PILES Kom'ad Haage, Esslingen-Kirnmichsweiler,Germany, as-

signor to Firma Delmag-Machinenfabrik Reinhold Dornfeld, Esslingen(Neckar), Germany Filed Apr. 20, 1959, Ser. No. 807,674 Claims priority,application Germany Apr. 26, 1958 1 Claim. (Cl. 123-7) The presentinvention relates to a method of pile driving and a pile driver. Withheretofore known pile drivera, the driving of piles and the like iseffected exclusively by blows. However, the driving of piles and thelike by blows has various drawbacks. Thus, for instance, such blowscause very high forces of inertia which are effective for an extremelyshort time only and which harmfully affect the material of the piledriver as well as of the pile being driven. On the other hand, aconsiderable shock loss is encountered which produces heat and plasticdeformation and likewise has a destroying effeet. It may also be addedthat the hard blow causes considerable noise which is audible for quitea distance and is a considerable nuisance in residential districts.

With heretofore known diesel hammers with which the blow effect duringthe driving of the pile is aided by the high combustion pressure, theadvancement of the pile stops only after the carrying capacity of thepile has reached six to seven times the maximum combustion pressure. Ifsuch a hammer would work with the combustion pressure only, in otherwords, if the blow effect would not be used, the advancement of the pilewould cease when its carrying capacity has reached 0.6 to 0.7 themaximum combustion pressure.

It is an object of the present invention so to modify the drivingoperation that it would be possible not to use the blow effect withoutencountering the premature ceasing of the penetration of the pile,thereby avoiding the above mentioned drawbacks due to the blow or hammereffect.

It is another object of this invention so to conduct the drivingoperation of a diesel hammer that the driving of the pile will beeffected by the combustion pressure only.

Another object consists in the provision of an improved pile driver.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawing, in which:

FIG. 1 is a vertical sect-ion through a hammer of a diesel hammer, saidhammer occupying its highest position.

FIG. 2 is a section similar to that of FIG. 1 but with the hammeroccupying its lowest position in which it exerts the highest pressure onthe pile to be driven.

The method according to the invention of driving a pile or the like bymeans of a high pressure diesel hammer is characterized primarily inthat the driving operation is efiected without a hammer efiect andexclusively by means of the combustion pressure of the diesel hammer insuch a way that by correspondingly dimensioning the piston surface, thecombustion pressure is increased at least up to the maximum desiredcarrying capacity of the pile to be driven the counter pressure of thecombustion gases enclosed in the compression chamber being absorbed bythe dropping mass of the hammer which without blow upon the pile isagain accelerated in upward direction.

This method may be carried out by employing a hammer having a pistonsurface of such magnitude that the maximum combustion pressure actingthereupon will be approximately from 1.4 to 2.5 times higher, than the rPatented Sept. 26, 19 61 ice maximum carrying capacity required by thepile to be driven. By selecting the combustion pressure, i.e. thespecific combustion pressure in atmospheres above at-: mosphericpressure multiplied by the piston surface, of such magnitude that thesaid combustion pressure alone, i.e. without a blow exerted by thehammer upon the pile, can drive the pile until the desired carryingcapacity of the pile has been obtained, the goal of-the invention isassured. The pile may thus be driven, at least up to this time, withouthammer blows. -In addition to the requirement that the combustionpressure is supposed to be approximately from 1.4 to 2.5 times as greatas the maximum required carrying capacity of the pile, the combustionpressure also meet the requirement that it will be effective for such atime that during such a combustion, the stroke performed by the pilehead will during this period be greater than the elastic resiliency ofthe pile and of the ground at said load. The. farther the combustionpressure exceeds the maximum carrying capacity of the pile, the less maybe the duration of the combustion pressure effect, and vice versa.

The increase in the specific pressure of the explosion gases alone wouldnot lead to the desired goal of effecting the drive without blowsbecause in such an instance the maximum combustion pressure with thenowadays customary stroke volumes and the customary ratios of stroke todiameter would have to increase to up from 500 to 800 atmospheres aboveatmospheric pressure, whereas 300 atmospheres above atmospheric pressureis nowadays the feasible limit of pressures occurring with dieselhammers. 1

The piston surface should therefore be of a magnitude which equals about1.7 to 3.0 that of diesel hammers of the same output. Since on the otherhand, the stroke volume can be enlarged only slightly, because otherwisethe jumping height of the hammer will become so great with only slightlypulling piles that again a blow will occur, the stroke may be reducedcorrespondingly so that a very short stroke machine will be created inwhich the quotient of stroke to piston diameter varies in instance fromabout 0.7 to 0.2, preferably from 0.5 to 0.3.

With reference to the drawing, the cylinder simultaneously serving ashammer is guided on a shaft 3 by means of a guiding slide 2. Piston 4having a diameter D rests through a blower hood 5 upon a pile 6. A fueltank 7 is arranged in the upper portion of cylinder 1 and surrounds afuel injection pump 8 which injects fuel into chamber 10 through theintervention of an injection nozzle 9. The explosion gases are adaptedto escape from this chamber through control slots 11 through whichcontrol slots also fresh air is adapted to be drawn Cylinder 1 drivingupwardly by explosion pressure is shown in FIG. 1 in its highest flyingposition.

FIG. 2 which also shows the stroke h shows the condition in which thecylinder has dropped to such an extent that the piston has overrun thecontrol slots 11 and is now located in its highest (innermost) positionat which the compression has reached its maximum. Shortly prior thereto,the fuel was injected which now is ignited in view of the highcompression temperature. The thus resulting high combustion pressure Pacts upon piston 4 which latter through connecting rod 41 and blowerhood 5 drives pile 6 into the ground because the combustion pressure -Pis higher than the resistance W of the pile to penetration. Thecombustion pressure acts upon the cylinder 1 and accelerates its massand thereby throws said mass upwardly whereupon a new cycle will start.A contact between cylinder 1 and the blower hood 5 will not occur withthis operation.

It is a well-known fact that diesel hammers with high compressionpressures start rather reluctantly at the i a V I 3 I beginning of thepile driving operation, i.e. when the pile has-still a very low drivingresistance. Therefore, it had to be ascertained whether the pile drivingwithout blow would become impossible by the fact that a pile driveraccording to the invention very large piston' sufiac'e and very highcompression "and combustion 'pressures insight at all start or continuerunning "when the drining of such light pile. However, it

has been found that the behavior :of the engine "as far as 'its'stazrtin'g is "C'Q'l'ltfiined does not :tl'epend alone on the pistonsurface but also on the stroke volume. inasnm'ch a's, however, thestroke volume is not materially difierent-over the heretofore fknownpile drivers, a star in'g will he assured with the :method according tothe invention and-the hamme'rs required -therefor.

----A's "will be evident from the above, with the method according tothe invention, the 'piles are driven by pure pressure as if they werepressed hydraulically. The essential difierence cmisists in that whenhydraulically pressing or driving, a counter bearing to be present whichis adapted to absorb -the required high pressure. In contrast thereto,with the method according 'to the invention, exclusively the droppinghammer which, without the exertion of a thlowupon the pile is then:acc'elerated in upward direction, will serve as counter bearing.

It is, of course, to be understood that the present 1 invention is, by'no means, limited to the particular on struction shown in the drawingsbut also comprises any modifications within the scope of the appendedclaim.

What I claim is: 7

A high pressure diesel driver for driving a pile by combustion pressureonly, which includes .a having an effective :piston and a pistonnodsqaroided with apfle-engaging member, and which also includes acylinder receiving said piston, said cylinder being movable with respectto said piston, said effective piston surface confining with saidcylinder a compression and combustion chamber, in which pile driver :thestroke of the cylinder relative to said piston divided by the pistondiameter is within the range of .from 0,7 to 0.2.

473,295 Great Britain Oct. '11, 4937?

